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Error code reference

Thor Kitchen Dishwasher Error Code E4

Overflow

Thor Kitchen codesThor Kitchen dishwasher codes

Overflow — some element of the dishwasher leaks.

First step from the service manual

Turn off the main water supply before calling service.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What E4 means on a Thor Kitchen dishwasher

The E4 error code on a Thor Kitchen dishwasher indicates an overflow condition, meaning water has accumulated in an area where it should not be present, typically the base pan located beneath the dishwasher tub. Most Thor Kitchen dishwashers use a float switch or overflow sensor in this base pan to detect unexpected water accumulation. When water reaches this sensor, it triggers E4 and halts operation to prevent further water damage to the surrounding cabinetry and flooring.

The overflow condition can originate from several points within the water circuit. A leaking door gasket, a cracked or loose hose connection, a faulty water inlet valve that fails to close fully, or a damaged pump housing can all allow water to migrate into the base pan. In some cases, excessive sudsing from the wrong detergent type or an overloaded detergent dispenser can cause water to spill past the door seal and pool beneath the unit.

Because the E4 code signals active or recent water intrusion, the immediate priority is shutting off the main water supply to the dishwasher before any further inspection or service. This prevents additional water from entering the machine while the source of the leak is being located. The base pan may need to be dried completely before the sensor will reset and allow normal operation to resume.

Source: manufacturer service documentation.

Common causes of E4

  1. 01

    Leaking or worn door gasket

    Part replacement

    The rubber seal around the dishwasher door can crack, harden, or pull away from its channel over time, allowing water to escape during a wash cycle and drip into the base pan. Inspect the gasket for visible tears, deformation, or debris preventing a proper seal.

  2. 02

    Loose or damaged hose connection

    Part replacement

    The inlet hose, drain hose, or internal circulation hoses can develop loose fittings or small cracks that drip water into the base pan during operation. Check all visible hose connections for moisture, mineral buildup, or signs of movement.

  3. 03

    Faulty water inlet valve

    Part replacement

    A water inlet valve that fails to close completely will allow water to continue entering the tub even when the dishwasher is not actively filling, eventually causing overflow into the base pan. This often presents as water found in the tub when the unit has been idle.

  4. 04

    Excessive sudsing from incorrect detergent

    Wiring / connection

    Using hand dish soap or a non-dishwasher detergent causes excessive foam that can overflow past the door seal and into the base pan. If the interior smells soapy or foam is visible, this is a likely contributor and no replacement parts are needed.

  5. 05

    Damaged pump housing or sump seal

    Part replacement

    The pump assembly or its surrounding sump seals can develop cracks or wear that allow water to leak into the base area during the wash or drain cycle. This type of leak typically requires disassembly of the lower dishwasher interior to inspect and confirm.

See the test procedure for each cause

Frequently asked questions about E4

What does E4 mean on a Thor Kitchen dishwasher?
E4 on a Thor Kitchen dishwasher signals an overflow condition, meaning water has been detected in the base pan beneath the dishwasher tub. The dishwasher stops operation automatically to prevent further water damage. The leak can come from the door gasket, hose connections, inlet valve, or internal pump components. The water supply should be shut off immediately before any inspection or service is performed.
Is it safe to keep using my Thor Kitchen dishwasher when E4 appears?
No, you should not continue running the dishwasher while E4 is active. The code indicates water is leaking into an area it should not reach, which poses a risk of water damage to your cabinetry, flooring, and nearby electrical components. Turn off the water supply to the appliance and leave it off until the source of the leak has been identified and repaired.
Will resetting the dishwasher clear the E4 error code?
Simply resetting the dishwasher is unlikely to permanently clear E4 if the underlying leak has not been fixed. The base pan may also need to be fully dried before the overflow sensor resets, as a wet sensor will continue triggering the code. Even if the error temporarily clears after drying, it will return if the leak source is not repaired.
How do I fix the E4 error on a Thor Kitchen dishwasher?
Start by shutting off the water supply and identifying the source of the leak. Check the door gasket for damage, inspect hose connections for looseness or cracks, and confirm you are using the correct dishwasher detergent. If no obvious external cause is found, a technician will need to access the base pan and internal components to locate the leak and replace the faulty part before returning the unit to service.
How much does it cost to repair an E4 error on a Thor Kitchen dishwasher?
Repair costs vary depending on the source of the leak. A door gasket replacement is typically the least expensive fix, with parts and labor generally ranging from around $75 to $175. Inlet valve or hose repairs may fall in the $100 to $250 range, while pump or sump seal repairs can cost more, potentially $200 to $400 or higher depending on the extent of the damage and local labor rates.

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